In vitro detection of C4d-fixing HLA alloantibodies: associations with capillary C4d deposition in kidney allografts.
Am J Transplant
; 8(1): 41-9, 2008 Jan.
Article
em En
| MEDLINE
| ID: mdl-17924995
ABSTRACT
Capillary C4d deposition is a valuable marker of antibody-mediated rejection (AMR). In this analysis, flow cytometric detection of alloantibody-triggered C4d deposition to HLA antigen-coated microparticles ([C4d]FlowPRA) was evaluated for its value as a marker for C4d deposition in renal allografts. For comparative analysis, 105 first renal biopsies performed for graft dysfunction and an equal number of concurrent sera were subjected to immunohistochemistry and [C4d] plus standard [IgG]FlowPRA, respectively. C4d deposition/fixation was detected in 17 biopsies and, applying [C4d]FlowPRA HLA class I and II screening, also in a small number of corresponding sera (N = 20). IgG reactivity detected by standard [IgG]FlowPRA was more frequent (49% of sera). Comparing [C4d]FlowPRA screening with capillary C4d staining, we found a high level of specificity (0.92 [95% confidence interval 0.86-0.98]), which far exceeded that calculated for [IgG]FlowPRA (0.60 [0.50-0.70]). [IgG]FlowPRA screening, however, turned out to be superior in terms of sensitivity (0.94 [0.83-1.05] vs. 0.76 [0.56-0.97] calculated for C4d-fixing panel reactivity). Remarkably, posttransplant single antigen testing for identification of complement-fixing donor-specific alloreactivities failed to improve the predictive value of FlowPRA-based serology. In conclusion, our results suggest that detection of complement-fixing HLA panel reactivity could provide a specific tool for monitoring of C4d-positive AMR.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fragmentos de Peptídeos
/
Complemento C4b
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Transplante de Rim
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Antígenos HLA
/
Isoanticorpos
/
Rim
Tipo de estudo:
Diagnostic_studies
/
Risk_factors_studies
Limite:
Adult
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Female
/
Humans
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Male
/
Middle aged
Idioma:
En
Revista:
Am J Transplant
Ano de publicação:
2008
Tipo de documento:
Article